Which shoulder test primarily assesses supraspinatus function?

• A. Drop arm test
• B. Empty can test (Jobe test)
• C. Hawkins-Kennedy test
• D. Gerber lift-off test

Answer: (B)

Testing supraspinatus function centers on how this muscle contributes to initiating and resisting arm abduction. The empty can test places the arm in the scapular plane with the shoulder in internal rotation (as if the patient is emptying a can) so the supraspinatus tendon is loaded during a resisted downward push. A weak or painful response during this resisted abduction identifies supraspinatus pathology and specifically assesses its function, making this test the most targeted choice.

The other tests probe different issues: a drop arm test looks for a rotator cuff tear by having the patient hold the arm abducted and then lower it, which indicates a tear but isn’t as specific to supraspinatus function; Hawkins-Kennedy is an impingement test stressing structures under the acromion; and the Gerber lift-off test evaluates subscapularis function, not supraspinatus.